I'm not aware of any particular term for this phenomenon, though I know the reality that you are talking about.

Geoffrey Sampson

This would be an example of ellipsis. This term describes the omission of “given” information, which in turn refers to knowledge assumed to be shared by participants in an exchange. “Given” information and its counterpart, “new” information, are also technical terms in linguistics.

Ellipsis contributes to discourse cohesion and economy in that it takes into account what participants know about the/their world, about each other, and about the context of the exchange itself.